That push-pull between belief and dismissiveness hints at a crossroads for liberals in the age of Trump. Unlike the fringy right, which has long relied on sites like Infowars and Breitbart to ratify its dreams and fears, the left lacks a well-developed infrastructure for spreading toxic and intoxicating innuendo. But progressives are angry and scared. They do seek out the pleasures of outrage and worldview confirmation. No political moment since at least the Nixon presidency has provided such fertile ground for conspiracy theories. ... Mensch’s scoops defy common sense and make a mockery of U.S. institutions. But so does Trump. Even her most tenuously sourced, outrageous tales feel like they’re on the cusp of tipping over into truth.